Stephens Tru-Sonic 15" woofers in Ampex Signature

[CoastinHome]

I attempted to do "strike-out" correction regarding the rear panel being stained. You must've read my posting before I ultimately deleted the comment. It appears that the 1958 had the rear panel stained:



The serial number tag is to the left of the tuner and attached with rivets on this unit. The 8102 had it attached with rivets to the back of the right side speaker enclosure as shown two posts above. The 8202-2 had it stapled to the back of the left side speaker enclosure. Useless trivia I suppose.

 

[CoastinHome]

1961 8202-2 driver configuration:
(I have not disassembled my speakers; the eBay pictures below are for reference and presumably represent the components in my console.)

Judging by the price alone those Altec Lansing woofers must be on par with the Trusonics.

 

[Omegaman]

Here is the label from my original Ampex console

 

[Omegaman]

THE MID-RANGE DRIVER

Well, I decided to get back in there and try to figure out the speaker code

Clear as mud

Same as #1 but upside down

 

[CoastinHome]

Here is the label from my original Ampex console
View attachment 1288580

Model 7208-2

My best guess of how this decodes:

7xxx = Crescendo

x0xx = First production year (1959): 954 (Beige) recorder, 402 preamp, 502 Stereo tuner (AM left; FM right) - plain beige faceplates
x1xx = Second production year (1960): 954 recorder, 403 preamp, 503 tuner - beige faceplates with striped overlay
x2xx = Third production year (1961): 952? recorder (charcoal/charcoal), 403 Preamp, 503 tuner – stainless faceplates
(Recorder models 952 and 954 are unenclosed equivalents to the 960 – gray and beige respectively. 952 is usually two-tone gray – there may be a different model designation for the newer charcoal gray model. Style revisions probably didn't coincide directly with the year model.)

xx02 = Contemporary Walnut
xx04 = Traditional Mahogany
xx06 = Contemporary Teak
xx08 = French Provincial

xxxx = 15W Amplifiers, 6973 Outputs

xxxx-2 = 30W Amplifiers, 6L6 Outputs (solid state rectifier)

Again, these are best guesses to be tested.

 

[CoastinHome]

One more thing, the pilot lamp voltage is 3.15VAC
Can I just use a GE47 6.3 there?

The parts list shows two different pilot lamps in the console.

(1.) p/n 61-0002 -- Lamp 6-8V .15 amp GE #47
(2.) Lamp, Pilot GE #12 (tuner dial)

They are probably running the GE47 6.3 at 50% to give it a soft glow as a pilot light.

 

[CoastinHome]

After quite a bit of searching I couldn't find the identical driver -- it may be a Jensen for Ampex custom version of the Jensen P8RX.

Below is a 1957 Jensen P8RX-C6126 (LS-541-137-B) from a 1960-61 Fisher.



It appears to be made from the same tooling as yours other than it's missing the tab to mount the speaker connections on a Bakelite strip such as that in the next picture of a pair of brown-frame P8RX.



The cone on yours appears to be identical to a Jensen P8-UM-C6661 -- which is a sealed-back unit:


So it's a pretty good bet that you have an Ampex by Jensen midrange driver.

(My console has an Ampex by ElectroVoice midrange. It appears identical to the EV SP8B -- other than it deletes the whizzer cone.)

 

[Dswankey]

I'll add this to the mix with regards to series

 

[CoastinHome]

Thanks Dswankey,

It looks like Ampex wasn't entirely consistent with their assignment of model numbers. Taking the full model line into consideration it appears that the second number represents a combination of model within the series and revision dates. The last two numbers can represent options in cabinet finish or choice of turntable (etc.)

Eventually I will start an "Ampex Console Registry" thread, starting from the top and drilling down. I've been saving photo sets of consoles and s/n tags I've encounter in ads.

From the info you added and the manual page below, these are (almost) knowns:


4000 Series = Ampex Custom, no tuner, 1 or 2 amplifier/speaker assemblies, 402 preamp, Garrard changer
4100 Series = (later) Ampex Custom, no tuner, 2 amplifier/speaker assemblies, 403 preamp, Garrard changer

4500 Series = Ampex Custom, w/502 tuner, 1 or 2 amplifier/speaker assemblies, 402 preamp, Garrard changer
4600 Series = (later) Ampex Custom, w/503 tuner, 2 amplifier/speaker assemblies, 403 preamp, Garrard changer

5000 Series = Ampex Concerto

6100 Series = Ampex Custom, no tuner, 2 amplifier/speaker assemblies, 402 or 403 preamp, 900 or 950 series recorder
6600 Series = Ampex Custom, 2 amplifier/speaker assemblies, 402 or 403 preamp, 900 or 950 series recorder
(Beige 904 half track / 954 stereo indicated on earlier units)

7000 Series = Ampex Crescendo, w/tuner, 950 Series recorder, Garrard changer

8000 Series = Ampex Signature (in Crescendo lineup?)
8002 = w/Garrard changer
8012 = w/Garrard 301

 

[Dswankey]

@CoastinHome

Nice work!!!!!

 

[Omegaman]

THE PRE-AMP AND TUNER MOUNTING BRACKET

This is the money shot

I'll need some:

sheet metal
90 Angle brackets
rivet gun

band-aids and eyewash

 

[Omegaman]

THE TAPE DECK DRAWER

Here is what my tape deck drawer looks like now

I'll have to fashion a bezel to trim the mounted unit

Anyone got a picture of the tape deck drawer with the unit pulled so I can see the mounting?

Here is the mounting from an Ampex 1260 portable case


The portable case uses little blocks of wood to stand off the bottom by 3/8"

 

[Dswankey]

@Omegaman

My 4100 series Crescendo originally had a TT however when I acquired it the TT was nowhere to be found. The TT would have been in the drawer. My unit only has one drawer.

Here's a pic from this thread, my unit is very similar



http://audiokarma.org/forums/index.php?threads/fun-with-ampex.307391/

As you can see the TT was mounted in the bottom drawer, which looks like the pic you just posted

 

[Dswankey]

Here's a thread that might give you an idea of how the RtR was mounted, not the best pics but hopefully it helps.

http://audiokarma.org/forums/index.php?threads/ampex-console.364855/

 

[Omegaman]

This cabinet mounts the tape deck with about 5/16th on each side left to trim

The two drawer Crescendo is much wider than this Signature


I pulled the original on/off lamp, a GE 46 screw-in 6-8 volt and it shows continuity

 

[Omegaman]

New capacitors for the crossovers

Here are the replacement caps



Here is the first side done and remounted


And the other side

Now I can stuff all that awesome spun glass fibers back in place

Both speakers ohm out at about 11.6

 

[CoastinHome]

Re: <<Anyone got a picture of the tape deck drawer with the unit pulled so I can see the mounting?>>

Omegaman,

My Signature drawer has the four blocks installed on the floor the same as the 1260 case. They are pin-nailed and glued. They are .115" thick. The deck is entirely supported on four top-hat-shaped rubber washers on top of these blocks. The washers in mine are smashed pretty flat but a reasonable approximation using a caliper is that they were .7" OD. The rim of the hat is .075"H and the top of the hat adds another.05" to the overall height. So overall height over the floor would be about 1/4".

Additional alignment is provided by the top plate rather than the 8 plywood strips in the upper corners. The top plate is walnut-veneered plywood. It measures .525" thick.

I don't think there's anything magic about the way the deck mounts beyond keeping the top surface of the deck flush with the top plate. If I was to re-engineer the installation I would have leave out the plywood blocks and have the deck sitting on four slabs of sorbothane (etc.) - perhaps between fender washers. I would cut the faceplate interior dimension so as to prevent it from contacting the deck at its upper perimeter.

If you need more info I do have the original full-size installation template with all the measurements... Somewhere.

 

[CoastinHome]

I'm sure you will mount your deck to the existing holes and then measure the size of the frame needed -- but just to give you an idea: My top frame measures 1.192" to the left of the deck, 1.175" to the right, .685 to the front and .825" to the back.

I better get back on task as we are expecting rain and I have furniture outside...

 

[CoastinHome]

Nice work!

Here's the drawer photo. This 1959 drawer had the original 954 deck. This one had standard 1/4" steel washers under the deck. The one nearest the exhaust vent hole is still in place in this picture. Total height of wood and washer is .165"H. It may well have had rubber washers above these. Bezel is .535" thick.



This isn't the same drawer I took the measurements from yesterday. The measurements I gave you yesterday were from a 1961 drawer with a 1250 deck. Given the timeline it's possible that the 1250 may have been an updated unit.

Here's what it looked like when it was installed (from the sellers eBay photos):



I wonder what the optimum criteria are for inserting pictures. When dragging and dropping the 97KB photo displays larger than the 1900KB photo from my phone.

 

[CoastinHome]

Top panel is actually veneered laminated sticks.


Some Ampex consoles used a cardboard tube as a fan shroud but apparently not here.